Journal of Geophysical Research: Biogeosciences最新文献

{"title":"Distinguishing the Impacts and Gradient Effects of Climate Change and Human Activities on Vegetation Cover in the Weihe River Basin, China","authors":"Wen-Bo Lv,&nbsp;Fang-Mei Liu,&nbsp;Kai Cai,&nbsp;Yue Cao,&nbsp;Meng-Ling Deng,&nbsp;Wei Liang,&nbsp;Jian-Wu Yan,&nbsp;Guang-Yu Wang","doi":"10.1029/2024JG008297","DOIUrl":"https://doi.org/10.1029/2024JG008297","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <p>Vegetation cover is crucial for ecosystem stability, responding sensitively to climate change and human activities, and is prone to irreversible degradation. However, the mechanisms driving vegetation variations due to natural and anthropogenic factors still need to be fully understood. This study focused on the Weihe River Basin to elucidate the response mechanism of vegetation cover change to climate change and human activities from 2001 to 2020. Long time-series multi-source data were combined with a pixel dichotomy model, Theil–Sen median trend analysis, and Mann-Kendall test to examine the trends and delineate five gradients in vegetation cover change. Additionally, Extreme Gradient Boosting, the Shapley value, and a structural equation model were employed to investigate the multidimensional response of vegetation cover in the basin as a whole and different vegetation cover gradients. The results revealed a general upward trend in vegetation coverage in the Weihe River Basin from 2001 to 2020. Topographic conditions and human activities were identified as primary influencers. Notably, accounting for climate change, particularly about changes in maximum climatic variables, was found to be essential, with temperature changes exerting a greater impact on vegetation cover variations compared to precipitation changes. The interaction between human activities, climate change, and topographic conditions can alter the intensity of each factor’s effect. The direction of indicators mentioned above varied across the vegetation cover gradients, emphasizing the need for localized strategies to improve vegetation. These findings offer valuable insights into ecological protection and vegetation restoration in the Weihe River Basin.</p>\u0000 </section>\u0000 </div>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142451740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temperature and Flow Control Organic Carbon Metabolism in Boreal Headwater Streams","authors":"F. M. Iannucci,&nbsp;J. B. Jones Jr.,&nbsp;K. L. Olson,&nbsp;M. E. Muscarella,&nbsp;E. R. Hotchkiss","doi":"10.1029/2024JG008281","DOIUrl":"https://doi.org/10.1029/2024JG008281","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <p>Metabolism in stream ecosystems alters the fate of organic carbon (OC) received from surrounding landscapes, but our understanding of in-stream metabolic processes in boreal ecosystems remains limited. Determining the factors that regulate OC metabolism will help predict how the C balance of boreal streams may respond to future environmental change. In this study, we addressed the question: what controls OC metabolism in boreal headwater streams draining catchments with discontinuous permafrost? We hypothesized that metabolism is collectively regulated by OC reactivity, phosphorus availability, and temperature, with discharge modulating each of these conditions. We tested these hypotheses using a combination of laboratory experiments and whole-stream ecosystem metabolism measurements throughout the Caribou-Poker Creeks Research Watershed (CPCRW) in Interior Alaska, USA. In the laboratory experiments, respiration and dissolved OC (DOC) removal were both co-limited by the supply of reactive C and phosphorus, but temperature and residence time acted as stronger controls of DOC removal. Ecosystem respiration (ER) was largely predicted by discharge and site, with some variance explained by gross primary production (GPP) and temperature. Both ER and GPP varied inversely with watershed permafrost extent, with an inverse relationship between temperature and permafrost extent providing one plausible explanation. Our results provide some of the first evidence of a functional response to permafrost thaw in stream ecosystems and suggest the role of metabolism in landscape C cycling may increase as climate change progresses.</p>\u0000 </section>\u0000 </div>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142451187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assimilation of Sentinel-1 Backscatter to Update AquaCrop Estimates of Soil Moisture and Crop Biomass","authors":"Shannon de Roos,&nbsp;Michel Bechtold,&nbsp;Louise Busschaert,&nbsp;Hans Lievens,&nbsp;Gabrielle J. M. De Lannoy","doi":"10.1029/2024JG008231","DOIUrl":"https://doi.org/10.1029/2024JG008231","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <p>This study assesses the potential of regional microwave backscatter data assimilation (DA) in AquaCrop for the first time, using NASA's Land Information System. The objective is to assess whether the assimilation setup can improve surface soil moisture (SSM) and crop biomass estimates. SSM and crop biomass simulations from AquaCrop were updated using Sentinel-1 synthetic aperture radar observations, over three regions in Europe in two separate DA experiments. The first experiment concerned updating SSM using VV-polarized backscatter and the corrections were propagated via the model to the biomass. In the second experiment, the DA setup was extended by also updating the biomass with VH-polarized backscatter. SSM was evaluated with local in situ data and with downscaled Soil Moisture Active Passive (SMAP) retrievals for all cropland grid cells, whereas crop biomass was compared to SMAP vegetation optical depth and the Copernicus dry matter productivity. The assimilation showed mixed results for root mean square error and Pearson's correlation, with slight overall improvements in the (anomaly) correlations of updated SSM relative to independent in situ and satellite data. By contrast, the biomass estimates obtained with backscatter DA did not agree better with reference data sets. Overall, the SSM evaluation showed that there is potential in using Sentinel-1 backscatter for assimilation in AquaCrop, but the present setup was not able to improve crop biomass estimates. Our study reveals how the complex interaction between SSM, crop biomass and backscatter affect the impact and performance of DA, offering insight into ways to optimize DA for crop growth estimation.</p>\u0000 </section>\u0000 </div>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JG008231","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142447643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A 14,000-Year Sediment Record of Mercury Accumulation and Isotopic Signatures From Lake Malaya Chabyda (Siberia)","authors":"Lara Hughes-Allen,&nbsp;Frédéric Bouchard,&nbsp;Boris K. Biskaborn,&nbsp;Sahara Cardelli,&nbsp;Dmitry A. Subetto,&nbsp;Laure Laffont,&nbsp;Jeroen E. Sonke","doi":"10.1029/2023JG007863","DOIUrl":"https://doi.org/10.1029/2023JG007863","url":null,"abstract":"<p>Eurasian permafrost soils contain large amounts of organic carbon (OC) and mercury (Hg), sequestered by vegetation during past and present interglacial periods. Lake sediment archives may help understand past OC and Hg dynamics and how they interact with climate-related variables. We investigated Hg accumulation, OC dynamics, and Hg and OC stable isotopes in a 14,000-year sediment record from Lake Malaya Chabyda (Central Yakutia, Russia). Sediment Hg was correlated to OC (<i>p</i> value &lt; 0.01), with lower OC and Hg accumulation rates (OCAR, HgAR) during the cold Younger Dryas (YD, 12,900–11,700 cal BP), when the lake level was low. Elevated sediment Δ²⁰⁰Hg (0.05‰ ± 0.11‰), representing dominant Hg^II deposition, and low δ¹³C, indicates low lake primary productivity during the YD. During the early Holocene, Δ²⁰⁰Hg and Δ¹⁹⁹Hg decreased, while δ¹³C, δ²⁰²Hg, OCAR, and HgAR increased, suggesting enhanced algal primary productivity in deeper, more turbid waters. From 4,100 cal BP to present, Hg/OC ratios and HgAR increased at constant OCAR, indicating an additional Hg source to the lake. Analysis of Hg isotopes suggests direct Hg⁰ uptake into lake waters, potentially driven by primary production and efficient Hg burial. Our observations suggest that the gradual climate warming since the Last Glacial Termination and into the early Holocene led to enhanced OC and Hg burial in northern lakes and watersheds. Late Holocene enhanced Hg burial, but not OC, is possibly related to a renewed increase in lake primary productivity. Continued global warming may lead to further Hg sequestration in northern aquatic ecosystems.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2023JG007863","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142449089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Droughts Amplify Soil Moisture Losses in Burned Forests of Southeastern Amazonia","authors":"Antônio C. Silveiro,&nbsp;Divino V. Silvério,&nbsp;Marcia N. Macedo,&nbsp;Michael T. Coe,&nbsp;Leandro Maracahipes,&nbsp;Maria Uribe,&nbsp;Leonardo Maracahipes-Santos,&nbsp;Paulo Tarso S. Oliveira,&nbsp;Ludmila Rattis,&nbsp;Paulo M. Brando","doi":"10.1029/2024JG008011","DOIUrl":"https://doi.org/10.1029/2024JG008011","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <p>Soil moisture is a crucial variable mediating soil-vegetation-atmosphere water exchange. As climate and land use change, the increased frequency and intensity of extreme weather events and disturbances will likely alter feedbacks between ecosystem functions and soil moisture. In this study, we evaluated how extreme drought (2015/2016) and postfire vegetation regrowth affected the seasonality of soil water content (0–8 m depth) in a transitional forest in southeastern Amazonia. The experiment included three treatment plots: an unburned Control, an area burned every three years (B3yr), and an area burned annually (B1yr) between 2004 and 2010. We hypothesized that (a) soil moisture at B1yr and B3yr would be higher than the Control in the first years postfire due to lower transpiration rates, but differences between burned plots would decrease as postfire vegetation regrew; (b) during drought years, the soil water deficit in the dry season would be significantly greater in all plots as plants responded to greater evaporative demand; and (c) postfire recovery in the burned plots would cause an increase in evapotranspiration over time, especially in the topsoil. Contrary to the first expectation, the burned plots had lower volumetric water content than the Control plot. However, we found that droughts significantly reduced soil moisture in all plots compared to non-drought years (15.6%), and this effect was amplified in the burned plots (19%). Our results indicate that, while compounding disturbances such as wildfires and extreme droughts alter forest dynamics, deep soil moisture is an essential water source for vegetation recovery.</p>\u0000 </section>\u0000 </div>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142447805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Water Column Nitrogen Removal During Storms in a Low-Order Watershed","authors":"E. Bacmeister,&nbsp;E. Peck,&nbsp;S. Bernasconi,&nbsp;S. Inamdar,&nbsp;J. Kan,&nbsp;Marc Peipoch","doi":"10.1029/2024JG008360","DOIUrl":"https://doi.org/10.1029/2024JG008360","url":null,"abstract":"<p>Water column removal in streams is a nitrogen (N) cycling pathway that has been historically overlooked. Studies filling this knowledge gap have focused on the role of water column N removal in mid-to-large-order rivers with consistently high suspended sediment concentrations. However, smaller streams may provide comparable suspended sediment concentrations during and after storm events, creating favorable conditions for water column N removal. To assess the presence, magnitude, and control of water column N removal during storms in low-order watersheds, we measured water column denitrification and heterotrophic assimilatory N uptake rates at three locations in a Mid-Atlantic watershed during five storm events of different magnitude, sediment loads, and nutrient availability. We found large variations in water column denitrification (0–5.56 mg N g⁻¹ d⁻¹) and assimilatory uptake (0.003–1.67 mg N g⁻¹ d⁻¹). Higher rates of N removal occurred during flow recession, with a correlation between suspended sediment organic matter content and denitrification. On average, denitrification rates in the water column were higher when flashy responses to storm events occurred. In contrast to denitrification, water column N removal rates (as both denitrification and heterotrophic assimilation) during storm events were comparable to those measured at baseflow in larger rivers. However, water column denitrification could only account for less than 10% of potential reach-scale N removal during most of the storm events. Our findings provide insight into the ecological relevance of small stream water columns and suggest that more research is needed to understand the magnitude of stream water column processing on watershed-scale N removal.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142435344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A New Coupled Biogeochemical Modeling Approach Provides Accurate Predictions of Methane and Carbon Dioxide Fluxes Across Diverse Tidal Wetlands","authors":"P. Y. Oikawa,&nbsp;D. Sihi,&nbsp;I. Forbrich,&nbsp;E. Fluet-Chouinard,&nbsp;M. Najarro,&nbsp;O. Thomas,&nbsp;J. Shahan,&nbsp;A. Arias-Ortiz,&nbsp;S. Russell,&nbsp;S. H. Knox,&nbsp;G. McNicol,&nbsp;J. Wolfe,&nbsp;L. Windham-Myers,&nbsp;E. Stuart-Haentjens,&nbsp;S. D. Bridgham,&nbsp;B. Needelman,&nbsp;R. Vargas,&nbsp;K. Schäfer,&nbsp;E. J. Ward,&nbsp;P. Megonigal,&nbsp;J. Holmquist","doi":"10.1029/2023JG007943","DOIUrl":"https://doi.org/10.1029/2023JG007943","url":null,"abstract":"<p>Tidal wetlands provide valuable ecosystem services, including storing large amounts of carbon. However, the net exchanges of carbon dioxide (CO₂) and methane (CH₄) in tidal wetlands are highly uncertain. While several biogeochemical models can operate in tidal wetlands, they have yet to be parameterized and validated against high-frequency, ecosystem-scale CO₂ and CH₄ flux measurements across diverse sites. We paired the Cohort Marsh Equilibrium Model (CMEM) with a version of the PEPRMT model called PEPRMT-Tidal, which considers the effects of water table height, sulfate, and nitrate availability on CO₂ and CH₄ emissions. Using a model-data fusion approach, we parameterized the model with three sites and validated it with two independent sites, with representation from the three marine coasts of North America. Gross primary productivity (GPP) and ecosystem respiration (R_eco) modules explained, on average, 73% of the variation in CO₂ exchange with low model error (normalized root mean square error (nRMSE) &lt;1). The CH₄ module also explained the majority of variance in CH₄ emissions in validation sites (<i>R</i>² = 0.54; nRMSE = 1.15). The PEPRMT-Tidal-CMEM model coupling is a key advance toward constraining estimates of greenhouse gas emissions across diverse North American tidal wetlands. Further analyses of model error and case studies during changing salinity conditions guide future modeling efforts regarding four main processes: (a) the influence of salinity and nitrate on GPP, (b) the influence of laterally transported dissolved inorganic C on R_eco, (c) heterogeneous sulfate availability and methylotrophic methanogenesis impacts on surface CH₄ emissions, and (d) CH₄ responses to non-periodic changes in salinity.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2023JG007943","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142435254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reconciling Top-Down and Bottom-Up Estimates of Ecosystem Respiration in a Mature Eucalypt Forest","authors":"N. J. Noh,&nbsp;A. A. Renchon,&nbsp;J. Knauer,&nbsp;V. Haverd,&nbsp;J. Li,&nbsp;A. Griebel,&nbsp;C. V. M. Barton,&nbsp;J. Yang,&nbsp;D. Sihi,&nbsp;S. K. Arndt,&nbsp;E. A. Davidson,&nbsp;M. G. Tjoelker,&nbsp;E. Pendall","doi":"10.1029/2024JG008064","DOIUrl":"https://doi.org/10.1029/2024JG008064","url":null,"abstract":"<p>Ecosystem respiration (R_eco) arises from interacting autotrophic and heterotrophic processes constrained by distinct drivers. Here, we evaluated up-scaling of observed components of R_eco in a mature eucalypt forest in southeast Australia and assessed whether a land surface model adequately represented all the fluxes and their seasonal temperature responses. We measured respiration from soil (R_soil), heterotrophic soil microbes (R_h), roots (R_root), and stems (R_stem) in 2018–2019. R_eco and its components were simulated using the CABLE–POP (Community Atmosphere-Biosphere Land Exchange–Population Orders Physiology) land surface model, constrained by eddy covariance and chamber measurements and enabled with a newly implemented Dual Arrhenius and Michaelis-Menten (DAMM) module for soil organic matter decomposition. Eddy-covariance based R_eco (R_eco.eddy, 1,439 g C m⁻² y⁻¹) was slightly higher than the sum of the respiration components (R_eco.sum, 1,295 g C m⁻² y⁻¹) and simulated R_eco (1,297 g C m⁻² y⁻¹). The largest mean contribution to R_eco was from R_soil (64%) across seasons. The measured contributions of R_h (49%), R_root (15%), and R_stem (22%) to R_eco.sum were very close to model outputs of 46%, 11%, and 22%, respectively. The modeled R_h was highly correlated with measured R_h (R² = 0.66, RMSE = 0.61), empirically validating the DAMM module. The apparent temperature sensitivities (Q₁₀) of R_eco were 2.22 for R_eco.sum, 2.15 for R_eco.eddy, and 1.57 for CABLE-POP. This research demonstrated that bottom-up respiration component measurements can be successfully scaled to eddy covariance-based R_eco and help to better constrain the magnitude of individual respiration components as well as their temperature sensitivities in land surface models.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JG008064","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142435253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Drought Timing Differentiates the Drought Responses of Vegetation Growth on the Tibetan Plateau","authors":"Zekai Meng,&nbsp;Xiuchen Wu,&nbsp;Yang Li,&nbsp;Xiaona Wang","doi":"10.1029/2024JG008179","DOIUrl":"https://doi.org/10.1029/2024JG008179","url":null,"abstract":"<p>The Tibetan Plateau, with its great hydrothermal gradients and diverse ecosystems, is considered vulnerable to climate change. Extreme drought can have detrimental effects on carbon sequestration in terrestrial ecosystems by disrupting plant eco-hydrological processes. Such effects are presumed to vary and depend on the vegetation types, environmental factors and drought properties. The drought timing has been widely highlighted in drought studies at both regional and site scales. However, the systematic insight into the impact of drought timing on the ecosystem functioning over the Tibetan Plateau remains unclear. In this study, we investigated the responses of vegetation greenness to meteorological drought and attributed them to the drought properties, climatic and edaphic factors. We found that the timing of drought plays a predominant role in regulating vegetation drought responses on the Tibetan Plateau. Notably, we observed significant differences in vegetation responses between late growing season drought and non-late growing season drought. In addition to drought timing, soil moisture and long-term hydrothermal conditions also played a significant role. Furthermore, our study revealed that alpine grassland was more sensitive to the drought timing, soil moisture and sand content than woody plants. We discovered a significant interplay between rainfall at hottest quarter and drought timing, with the role of drought timing weakening as the rainfall at hottest quarter increases. These findings underscore the crucial role of drought timing in shaping ecosystem functioning in response to the changing climate regime over the Tibetan Plateau and provide crucial insights into the improvement of land surface models.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142429870","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Climate-Induced Uncertainty in Modeling Gross Primary Productivity From the Light Use Efficiency Approach","authors":"Jiyan Wang,&nbsp;Yong Wang,&nbsp;Xinyao Xie,&nbsp;Wei Zhao,&nbsp;Changlin Wu,&nbsp;Xiaobin Guan,&nbsp;Tao Yang","doi":"10.1029/2024JG008394","DOIUrl":"https://doi.org/10.1029/2024JG008394","url":null,"abstract":"<p>Light use efficiency (LUE) models, along with satellite-based vegetation maps and climatic reanalysis products as drivers, are effective tools for estimating large-scale gross primary productivity (GPP). However, the climate-induced uncertainty in LUE-based GPP remains poorly understood, particularly the temporal scaling uncertainty from ignored climatic fluctuations. Here, two 1-hourly reanalysis products, along with site-based observations, were employed to drive a two-leaf LUE model at 194 eddy-covariance (EC) sites. The observation-driven and reanalysis-driven GPP at the 1-hourly resolution were evaluated against EC GPP to illustrate the uncertainty from reanalysis products, with mean absolute deviation (MAD) and Nash-Sutcliffe efficiency (NSE) as criterion. Moreover, the climate-induced temporal scaling uncertainty was characterized by comparing distributed GPP (modeled with 1-hourly resolution climatic drivers) and lumped GPP (modeled with 6-hourly resolution climatic drivers). At the 1-hourly resolution, results demonstrated that the reanalysis-driven GPP showed a weaker relationship with EC GPP (MAD = 0.14 gC m⁻²h⁻¹, NSE = 0.48) than the observation-driven GPP (MAD = 0.12 gC m⁻²h⁻¹, NSE = 0.60), confirming the nonnegligible climate-induced uncertainty from reanalysis products. Additionally, the climate-induced uncertainty arising from gridded radiation was found to be significantly larger than that associated with temperature and vapor pressure deficit (VPD). At the 6-hourly resolution, both the observation-driven and reanalysis-driven lumped GPP exhibited a lower relationship with EC GPP (MAD = 0.63 gC m⁻²6h⁻¹, NSE = 0.54) than the corresponding distributed GPP (MAD = 0.57 gC m⁻²6h⁻¹, NSE = 0.59), demonstrating that the climate-induced temporal scaling uncertainty in 6-hourly GPP estimates was significantly apparent. This study emphasizes the imperative to refine reanalysis products for more precise capture of short-term fluctuations and to reduce scaling uncertainties in coarse temporal resolution GPP estimates.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142429592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}